The Biology of Treating Blindness with Stem Cells

His plan involves coaxing stem cells to become sheets of precious cone photoreceptors – the eye’s light-sensitive cells – and then transplanting them into blind eyes to restore vision.

Dr. Bernier made headlines a few years ago with his tremendously important FFB-funded discovery that uncovered an efficient and effective method to coax stem cells into becoming cone photoreceptors. Since then, he has been fine-tuning his approach in the laboratory with the clear goal of moving toward a clinical trial. Last year, he launched the company StemAxon and began assembling key team members to accelerate his path to the clinic.

Will his cone photoreceptor transplantation approach work for you? When asked this question, Dr. Bernier answers honestly and cautiously: “In order to answer this question, I need to know the biology behind the disease.” First and foremost, Dr. Bernier is a scientist who is careful to not overpromise or over-hype the potential of his approach. He is quite optimistic, however, about its potential to work for Stargardt disease, an inherited blinding eye disorder that usually begins during the teenage years and leads to the progressive loss of central vision.

For Dr. Bernier, it makes sense to start by focusing on Stargardt disease because there is strong scientific evidence to show that it will work. Why? Because his plan involves transplanting sheets of purified cone photoreceptors into the area of the eye where they have been lost (the fovea); the loss of these cells in this area is what happens in Stargardt disease. Furthermore, there is evidence that diseased cone photoreceptors play an important role in the progression of Stargardt disease. Because of this, Dr. Bernier predicts that replacing diseased cone photoreceptors with new, healthy cells might halt further disease progression.

He is cautiously optimistic that his approach of transplanting cone photoreceptor sheets might also work as a treatment for other eye diseases where blindness results from the loss of cone photoreceptors. This is true in many blinding eye diseases, including age-related macular degeneration and late-stage retinitis pigmentosa (RP).

Dr. Bernier’s stem cell transplantation approach is appealing because it harnesses the unparalleled power of biology to produce a product that works. During his career in vision science, Dr. Bernier has learned an enormous amount about how the eye develops and how different cells function during this developmental process. His specialized knowledge led him to identify a chemical cocktail that can quickly transform stem cells into cone photoreceptors. This approach is amazing because it is based in biology; stem cells become photoreceptors because they are tricked into following a “normal” developmental pathway.

To really evaluate if Dr. Bernier’s approach might work for your disease, it’s important to learn as much as you can about how your disease affects the different cells of your body. For example, do you have a genetic mutation that is primarily affecting your cone photoreceptor cells, like in Stargardt disease? Or, does your disease impact many different cell types in your eye, such as the rod and cone photoreceptor cells, which are affected in RP? Or, does your disease also affect other parts of your body (like in Bardet-Biedl syndrome)? Why does it matter to find answers to these questions? Because they lay the groundwork for understanding why and how an experimental therapy might work. At the same time, this information offers clues to understand why a therapy doesn’t work. This is why the FFB continues to fund research into a variety of different blinding eye diseases; this knowledge is essential to ensure the development of effective therapies.

Biology matters because it is at the heart of why blinding eye diseases occur. Biology also holds the key to developing effective treatments, including Dr. Bernier’s promising plan to restore vision by transplanting cone photoreceptors.